Is there a UseCase for Snap to Volume?
It's very useful for rigging. Most of the time before the actual rigging you would want your rig bones inside mesh (probably around the center), but actually getting bones inside could be a problem that often requires moving around ortho views and dragging bones on 1 axis at at a time. With this snapping you can select joint and snap it to around the center  of arm or leg, do it for other joints, fix rotation and that's about it. Thought it doesn't work that well with complex shapes like hips or shoulders.